Waterville, city (1990 pop. 17,173), Kennebec co., S Maine, at the falls of the Kennebec River; settled 1754, inc. as a city 1888. It is the trade and medical center of a lake resort area, with textile and paper and pulp mills. During the early 1900s, Waterville had five shipyards that built many ocean and river vessels. Colby College and Thomas College are there.